Resolve "Building cookbook fails with ninja"

There was actually 3 fixes:

• call pdflatex directly instead of using the makefile produced by Sphinx
• fix the special characters in Laurențiu
• fix the missing version number (lost since !235 (merged) I guess)

Closes #1837 (closed)

A few refs:

• https://en.wikipedia.org/wiki/Romanian_alphabet#(La)TeX
• http://www.sphinx-doc.org/en/master/latex.html